WO2025071341A1 - Method and device for receiving downlink control information in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to a method performed by a terminal in a wireless communication system, the method comprising the steps of: receiving, from a base station, downlink control information (DCI) including a bandwidth part (BWP) indicator field and a first field; and performing DCI size alignment for the first field included in the DCI and a second field required for DCI format interpretation for a BWP indicated by the BWP indicator field corresponding to the first field, wherein the DCI is related to multi-cell scheduling, and if the first field includes a plurality of first blocks corresponding to respective cells configured for the multi-cell scheduling, the DCI size alignment may be applied on the basis of a block unit.

Description

Method and device for receiving downlink control information in a wireless communication system

The present disclosure relates to the operation of a terminal and a base station in a communication system. Specifically, the present disclosure relates to a method and device for a terminal to transmit and receive data through a plurality of cells with one downlink control information.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band, such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (㎜Wave), such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced by one-tenth.

In the early stages of 5G mobile communication technology, the goal was to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). The technologies included beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2 Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

Currently, discussions are underway on improving and enhancing the initial 5G mobile communication technology in consideration of the services that the 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

In addition, standardization of wireless interface architecture/protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures is also in progress, and standardization of system architecture/services for 5G baseline architecture (e.g. Service based Architecture, Service based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal is also in progress.

When such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, which will require enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, AI service support, metaverse service support, drone communications, etc. using extended reality (XR), artificial intelligence (AI), and machine learning (ML) to efficiently support augmented reality (AR), virtual reality (VR), and mixed reality (MR).

In addition, the development of these 5G mobile communication systems will require new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, and AI (Artificial Intelligence) from the design stage and AI-based communication technology that implements end-to-end AI support functions to realize system optimization, and ultra-high-performance communication and computing resources to provide services with a level of complexity that goes beyond the limits of terminal computing capabilities. It could serve as a basis for the development of next-generation distributed computing technologies that utilize this.

As described above and with the development of wireless communication systems, various services have become available, and methods for providing these services smoothly are required.

The disclosed embodiment is intended to provide a device and method capable of effectively providing a service in a mobile communication system.

The present disclosure proposes a method and device for determining a scheduled cell in a communication system.

The present disclosure proposes a method for indicating a cell to be scheduled in a DCI that schedules multiple cells.

The present disclosure relates to a method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, downlink control information including a bandwidth part (BWP) indicator field and a first field; and performing DCI size alignment for a second field included in the DCI and necessary for interpreting a DCI format for a BWP indicated by the BWP indicator field, the second field corresponding to the first field, wherein when the DCI is related to multi-cell scheduling and the first field includes a plurality of first blocks corresponding to respective cells set for the multi-cell scheduling, the DCI size alignment can be applied on a block-by-block basis.

The present disclosure relates to a terminal in a wireless communication system, the terminal including: a transceiver; and a controller connected to the transceiver, wherein the controller is configured to receive, from a base station, downlink control information including a bandwidth part (BWP) indicator field and a first field, and perform DCI size alignment for the first field included in the DCI and a second field necessary for interpreting a DCI format for a BWP indicated by the BWP indicator field corresponding to the first field, wherein when the DCI is related to multi-cell scheduling and the first field includes a plurality of first blocks corresponding to respective cells set for the multi-cell scheduling, the DCI size alignment can be applied on a block-by-block basis.

The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

FIG. 4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system.

FIG. 5 is a diagram showing an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in 5G.

FIG. 6 is a diagram for explaining a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and rate matching resources in a wireless communication system according to one embodiment of the present disclosure.

FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

FIG. 9 is a diagram illustrating an example of time axis resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

FIG. 10 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

FIG. 11 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 12 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 13 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 14 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 15 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 16 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 17 is a diagram illustrating an example of DCI field length alignment according to one embodiment of the present disclosure.

FIG. 18 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

FIG. 19 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure are omitted. This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary descriptions.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are given the same reference numbers.

The advantages and features of the present disclosure, and the methods for achieving them, will become clear with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present disclosure complete and to fully inform a person having ordinary skill in the art to which the present disclosure belongs of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the disclosure. In addition, when describing the present disclosure, if it is determined that a specific description of a related function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the present disclosure.

Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal that a base station transmits to a terminal, and uplink (UL) refers to a wireless transmission path of a signal that a terminal transmits to a base station. In addition, although an LTE or LTE-A system may be described as an example below, embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Accordingly, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~parts' may be implemented to play one or more CPUs within the device or secure multimedia card. Also, in an embodiment, the '~part' may include one or more processors.

Wireless communication systems are evolving from providing initial voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or a control signal to a base station (eNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or a control signal to a terminal. The above multiple access method typically allocates and operates time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality, thereby distinguishing the data or control information of each user.

As a future communication system after LTE, that is, a 5G communication system must be able to freely reflect various requirements of users and service providers, and therefore services that simultaneously satisfy various requirements must be supported. Services considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

eMBB aims to provide a data transmission rate that is higher than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, eMBB should be able to provide a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. In addition, a 5G communication system should provide an increased user perceived data rate while providing the peak data rate. To meet these requirements, it requires improvements in various transmission/reception technologies, including further improved multi-input multi-output (MIMO) transmission technology. In addition, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, a 5G communication system can satisfy the data transmission rate required by the 5G communication system by using a wider frequency bandwidth than 20 MHz in the 3 to 6 GHz or higher frequency band.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC requires support for mass terminal connection, improved terminal coverage, improved battery life, and reduced terminal costs within a cell. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (e.g., 1,000,000 terminals/km2) within a cell. In addition, terminals supporting mMTC are likely to be located in shadow areas that cells do not cover, such as basements of buildings, due to the nature of the service, and thus may require wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC must be composed of low-cost terminals, and since it is difficult to frequently replace the terminal batteries, a very long battery life time, such as 10 to 15 years, may be required.

Finally, URLLC is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services such as remote control of robots or machinery, industrial automation, unmanaged aerial vehicles, remote health care, and emergency alert can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time, has a requirement of a packet error rate of less than 10 ^-5 . Therefore, for a service supporting URLLC, a 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, a design requirement may be required to allocate wide resources in the frequency band to secure the reliability of the communication link.

The three services of 5G, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission and reception techniques and transmission and reception parameters can be used between services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[NR Time-Frequency Resource]

Below, the frame structure of the 5G system is described in more detail with reference to the drawings.

Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

(일례로 12)개의 연속된 RE들은 하나의 자원 블록(Resource Block, RB, 104)을 구성할 수 있다. The horizontal axis of Fig. 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain

(For example, 12) consecutive REs can form one Resource Block (RB, 104).

FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

)=14). 1 서브프레임(201)은 하나 또는 복수 개의 슬롯(202, 203)으로 구성될 수 있으며, 1 서브프레임(201)당 슬롯(202, 203)의 개수는 부반송파 간격에 대한 설정 값 μ(204, 205)에 따라 다를 수 있다. 도 2의 일 예에서는 부반송파 간격 설정 값으로 μ=0(204)인 경우와 μ=1(205)인 경우가 도시되어 있다. μ=0(204)일 경우, 1 서브프레임(201)은 1개의 슬롯(202)으로 구성될 수 있고, μ=1(205)일 경우, 1 서브프레임(201)은 2개의 슬롯(203)으로 구성될 수 있다. 즉 부반송파 간격에 대한 설정 값 μ에 따라 1 서브프레임 당 슬롯 수(

)가 달라질 수 있고, 이에 따라 1 프레임 당 슬롯 수(

)가 달라질 수 있다. 각 부반송파 간격 설정 μ에 따른

및

는 하기의 표 1로 정의될 수 있다.Fig. 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot (

)=14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of one slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of two slots (203). That is, depending on the setting value μ for the subcarrier spacing, the number of slots (

) may vary, and accordingly the number of slots per frame (

) may vary. Depending on the subcarrier spacing setting μ

and

can be defined as Table 1 below.

[Bandwidth Part (BWP)]

Next, the bandwidth part (BWP) setting in the 5G communication system will be specifically explained with reference to the drawing.

FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

Fig. 3 shows an example in which the UE bandwidth (300) is set to two bandwidth parts, namely, bandwidth part #1 (BWP#1) (301) and bandwidth part #2 (BWP#2) (302). The base station can set one or more bandwidth parts to the UE, and can set information such as Table 2 below for each bandwidth part.

Of course, it is not limited to the above example, and in addition to the above setting information, various parameters related to the bandwidth portion can be set for the terminal. The above information can be transmitted from the base station to the terminal through upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal through RRC signaling or dynamically transmitted through DCI (Downlink Control Information).

According to some embodiments, a terminal before an RRC (Radio Resource Control) connection can be configured with an initial bandwidth portion (Initial BWP) for initial access from a base station through a MIB (Master Information Block). More specifically, the terminal can receive, in the initial access phase, configuration information about a control region (Control Resource Set, CORESET) and a search space where a PDCCH for receiving system information (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1) required for initial access can be transmitted, through the MIB. The control region and the search space configured by the MIB may each be regarded as identifier (Identity, ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control region #0 through the MIB. In addition, the base station can notify the terminal of configuration information about a monitoring period and occasion for control region #0, that is, configuration information for search space #0, through the MIB. The terminal may regard the frequency range set as control area #0 obtained from the MIB as the initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion may be regarded as 0.

The settings for the bandwidth portion supported by the above 5G can be used for various purposes.

In some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, the base station can set the frequency position (setting information 2) of the bandwidth portion to the terminal, thereby allowing the terminal to transmit and receive data at a specific frequency position within the system bandwidth.

In addition, according to some embodiments, a base station may set multiple bandwidth portions to a terminal for the purpose of supporting different numerologies. For example, in order to support both data transmission and reception using a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz for a certain terminal, two bandwidth portions may be set with subcarrier spacings of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data is to be transmitted and received at a specific subcarrier spacing, a bandwidth portion set to the corresponding subcarrier spacing may be activated.

In addition, according to some embodiments, for the purpose of reducing power consumption of the terminal, the base station may set bandwidth portions having different sizes of bandwidths to the terminal. For example, if the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz, and always transmits and receives data with the bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring for an unnecessary downlink control channel with a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. In order to reduce power consumption of the terminal, the base station may set a bandwidth portion with a relatively small bandwidth, for example, a bandwidth portion of 20 MHz, to the terminal. In a situation where there is no traffic, the terminal may perform a monitoring operation in the bandwidth portion of 20 MHz, and when data is generated, may transmit and receive data in the bandwidth portion of 100 MHz according to the instructions of the base station.

In the method for setting the bandwidth part, terminals before RRC connection (Connected) can receive setting information for the initial bandwidth part (Initial Bandwidth Part) through MIB (Master Information Block) in the initial access stage. More specifically, the terminal can receive a control area (Control Resource Set, CORESET) for a downlink control channel on which DCI (Downlink Control Information) for scheduling SIB (System Information Block) can be transmitted from the MIB of PBCH (Physical Broadcast Channel). The bandwidth of the control area set by MIB can be regarded as the initial bandwidth part, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which SIB is transmitted through the set initial bandwidth part. In addition to the purpose of receiving SIB, the initial bandwidth part can also be utilized for other system information (Other System Information, OSI), paging, and random access.

When one or more bandwidth part indicators are set for a terminal, the base station can instruct the terminal to change (or switch, transition) the bandwidth part using the bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station can instruct the terminal to bandwidth part #2 (302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

As described above, since DCI-based bandwidth part change can be indicated by DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth part change request, it should be able to perform reception or transmission of PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard stipulates requirements for the delay time (T _BWP ) required when changing the bandwidth part, and can be defined as in Table 3, for example.

The requirement for bandwidth part change delay time supports type 1 or type 2 depending on the capability of the terminal. The terminal can report the type of bandwidth part delay time that it can support to the base station.

According to the requirement on the bandwidth part change delay time mentioned above, when the terminal receives the DCI including the bandwidth part change indicator in slot n, the terminal can complete the change to the new bandwidth part indicated by the bandwidth part change indicator no later than slot n+T _BWP , and can perform transmission and reception for the data channel scheduled by the corresponding DCI in the changed new bandwidth part. When the base station wants to schedule the data channel with the new bandwidth part, the base station can determine the time domain resource allocation for the data channel by considering the bandwidth part change delay time (T _BWP ) of the terminal. That is, when the base station schedules the data channel with the new bandwidth part, the data channel can be scheduled after the bandwidth part change delay time in the method of determining the time domain resource allocation for the data channel. Accordingly, the terminal may not expect that the DCI indicating the bandwidth part change indicates a slot offset (K0 or K2) value smaller than the bandwidth part change delay time (T _BWP ).

If the terminal receives DCI indicating a bandwidth change (e.g., DCI format 1_1 or 0_1), the terminal may not perform any transmission or reception during a time period corresponding to a time interval from the third symbol of a slot in which a PDCCH including the DCI is received to the start point of a slot indicated by a slot offset (K0 or K2) value indicated by a time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[SS/PBCH Block]

Next, we will explain the SS (Synchronization Signal)/PBCH block in 5G.

An SS/PBCH block may refer to a physical layer channel block consisting of a PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

- PSS: A signal that serves as a reference for downlink time/frequency synchronization and provides some information about the cell ID.

- SSS: It serves as a reference for downlink time/frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for demodulation of PBCH.

- PBCH: Provides essential system information required for transmission and reception of data channels and control channels of the terminal. Essential system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, etc.

- SS/PBCH block: An SS/PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS/PBCH blocks can be transmitted within 5ms, and each SS/PBCH block transmitted can be distinguished by an index.

The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH, and set control region (Control Resource Set; CORESET) #0 (which may correspond to a control region with a control region index of 0) therefrom. The terminal can monitor control region #0, assuming that the selected SS/PBCH block and DMRS (Demodulation Reference signal) transmitted in control region #0 are QCL (Quasi Co Location). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (Random Access Channel) related configuration information required for initial access from the received system information. The terminal can transmit PRACH (Physical RACH) to a base station considering the selected SS/PBCH index, and the base station receiving the PRACH can obtain information on the SS/PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among each SS/PBCH block and monitor the control region #0 associated with it.

[PDCCH: DCI related]

Next, we will specifically explain downlink control information (DCI) in the 5G system.

In a 5G system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) is transmitted from a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields selected between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

DCI can be transmitted through PDCCH (Physical Downlink Control Channel) which is a physical downlink control channel after going through channel coding and modulation process. CRC (Cyclic Redundancy Check) is attached to DCI message payload, and CRC can be scrambled with RNTI (Radio Network Temporary Identifier) corresponding to the identity of UE. Different RNTIs can be used depending on the purpose of DCI message, such as UE-specific data transmission, power control command, or random access response. That is, RNTI is not transmitted explicitly, but is included in the CRC calculation process and transmitted. When receiving DCI message transmitted on PDCCH, UE checks CRC using allocated RNTI, and if CRC check result is correct, UE can know that the message was transmitted to UE.

For example, a DCI scheduling a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a Paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 4.

DCI format 0_1 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 with the CRC scrambled with C-RNTI can include, for example, the information in Table 5.

DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 6.

DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the information in Table 7.

[PDCCH: CORESET, REG, CCE, Search Space]

Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

FIG. 4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. FIG. 4 illustrates an example in which two control regions (Control Region #1 (401), Control Region #2 (402)) are set within a UE bandwidth part (410) in the frequency axis and within one slot (420) in the time axis. The control regions (401, 402) can be set to specific frequency resources (403) within the entire UE bandwidth part (410) in the frequency axis. The time axis can be set to one or more OFDM symbols, and this can be defined as the control region length (Control Resource Set Duration, 404). Referring to the illustrated example of FIG. 4, Control Region #1 (401) is set to a control region length of two symbols, and Control Region #2 (402) is set to a control region length of one symbol.

The control region in the aforementioned 5G can be set by the base station to the terminal through upper layer signaling (e.g., system information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Setting the control region to the terminal means providing information such as the control region identifier (Identity), the frequency location of the control region, and the symbol length of the control region. For example, it can include the information in Table 8.

In Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal)/PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control region.

FIG. 5 is a diagram showing an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G. According to FIG. 5, a basic unit of time and frequency resources constituting a control channel can be referred to as a REG (Resource Element Group, 503), and a REG (503) can be defined as 1 OFDM symbol (501) in the time axis and 1 PRB (Physical Resource Block, 502) in the frequency axis, that is, 12 subcarriers. A base station can connect REGs (503) to configure a downlink control channel allocation unit.

As illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 504), 1 CCE (504) can be composed of multiple REGs (503). Taking the REG (503) illustrated in FIG. 5 as an example, the REG (503) can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), 1 CCE (504) can be composed of 72 REs. When a downlink control region is set, the region can be composed of multiple CCEs (504), and a specific downlink control channel can be mapped to one or multiple CCEs (504) and transmitted according to the aggregation level (AL) within the control region. CCEs (504) within the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

The basic unit of the downlink control channel illustrated in FIG. 5, that is, the REG (503), may include both the REs to which the DCI is mapped and the areas to which the DMRS (505), which is a reference signal for decoding the REs, is mapped. As in FIG. 5, three DMRSs (505) may be transmitted in one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL = L, one downlink control channel may be transmitted through L CCEs. The terminal must detect a signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates, which are CCEs that a terminal should attempt to decode at a given aggregation level. Since there are multiple aggregation levels that form a single bundle with 1, 2, 4, 8, and 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

The search space can be classified into a common search space and a UE-specific search space. A certain group of UEs or all UEs can search the common search space of the PDCCH to receive cell-common control information such as dynamic scheduling for system information or a paging message. For example, PDSCH scheduling allocation information for transmission of SIB including operator information of the cell can be received by searching the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs or all UEs must receive the PDCCH, it can be defined as a set of pre-promised CCEs. UE-specific scheduling allocation information for PDSCH or PUSCH can be received by searching the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the identity of the UE and various system parameters.

In 5G, parameters for a search space for PDCCH can be set from a base station to a terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol in a slot for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, the control region index to be monitored in the search space, etc. to the terminal. For example, it can include the information of Table 9.

Depending on the configuration information, the base station may configure one or more search space sets for the terminal. According to some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal, and configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

According to the configuration information, one or more search space sets may exist in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be set as the common search space, and search space set #3 and search space set #4 may be set as the terminal-specific search space.

In the common search space, the following combinations of DCI formats and RNTIs can be monitored, although they are not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

- DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

- DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored, although they are not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

- DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

The RNTIs specified may follow the definitions and uses below.

C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes.

TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes.

CS-RNTI (Configured Scheduling RNTI): For terminal-specific PDSCH scheduling purposes that are set semi-statically.

RA-RNTI (Random Access RNTI): For PDSCH scheduling in the random access phase.

P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control command for PUSCH.

TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

The DCI formats specified above may follow definitions such as the examples in Table 10.

In 5G, the search space of aggregation level L in the control domain p and the search space set s can be expressed as shown in the following mathematical expression 1.

: 집성 레벨-

: Integration level

: 캐리어(Carrier) 인덱스-

: Carrier Index

: 제어영역 p 내에 존재하는 총 CCE 개수-

: Total number of CCEs present within the control region p

: 슬롯 인덱스-

: slot index

집성 레벨 L의 PDCCH 후보군 수-

Number of PDCCH candidates for aggregation level L

집성 레벨 L의 PDCCH 후보군 인덱스-

PDCCH candidate index of aggregation level L

-

-

단말 식별자-

Terminal identifier

값은 공통 탐색공간의 경우 0에 해당할 수 있다.

The value can be 0 for a common search space.

값은 단말-특정 탐색공간의 경우, 단말의 신원(C-RNTI 또는 기지국이 단말에게 설정해준 ID)과 시간 인덱스에 따라 변하는 값에 해당할 수 있다.

In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set to the terminal by the base station) and the time index.

In 5G, since multiple search space sets can be set with different parameters (e.g., the parameters in Table 9), the set of search space sets monitored by the terminal at each point in time can be different. For example, if search space set #1 is set with an X-slot period and search space set #2 is set with a Y-slot period and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a specific slot, or can monitor either search space set #1 or search space set #2 in a specific slot.

[PDSCH/PUSCH: Frequency resource allocation related]

FIG. 7 is a diagram illustrating an example of frequency-axis resource allocation of a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) in a wireless communication system according to one embodiment of the present disclosure.

Figure 7 is a diagram illustrating three frequency axis resource allocation methods, type-0 (7-00), type-1 (7-05), and dynamic switch (7-10), which can be configured through an upper layer in an NR wireless communication system.

Referring to FIG. 7, if a terminal is configured to use only type-0 resource allocation through upper layer signaling (7-00), some downlink control information (DCI) that allocates PDSCH/PUSCH to the terminal includes a bitmap consisting of N _RBG bits. Here, N _RBG represents the number of RBGs (resource block groups) determined according to the BWP size allocated by the BWP indicator and the upper layer parameter rbg-Size as shown in [Table 11] below, and data is transmitted to the RBG indicated as 1 by the bitmap.

이다. 여기서 첫번째 RBG는

개의 RB들을 포함하고, 마지막 RBG는

이면,

개의 RB들을 포함하고, 그렇지 않으면,

개의 RB들을 포함한다. 나머지 RBG들은 P개의 RB들을 포함한다. 여기서 P는 표 11에 따라 결정된 nominal RBG의 수이다. The size of the BWP is the number of RBs included in the BWP. More specifically, when type-0 resource allocation is instructed, the length of the frequency domain resource assignment (FDRA) field of the DCI received by the terminal is equal to the number of RBGs (N _RBG ).

Here, the first RBG is

It contains RBs of the dog, and the last RBG is

On the other hand,

Contains the RBs of the dog, otherwise,

contains RBs of the dog. The remaining RBGs contain P RBs, where P is the number of nominal RBGs determined according to Table 11.

Resource Allocation Type 2

- RB allocation information can be notified from the base station to the terminal as a set of M interlace indices.

은 공통 RB

들로 구성할 수 있고, M은 표 12와 같이 정의될 수 있다.- Interlace index

Silver is common RB

can be composed of fields, and M can be defined as in Table 12.

와 공통 RB

와의 관계는 다음같이 정의될 수 있다.RB in interlace m and bandwidth part i

and common RB

The relationship with can be defined as follows.

■

is the common resource block where bandwidth part starts relative to common resource block 0. u is subcarrier spacing index■ where

is the common resource block where bandwidth part starts relative to common resource block 0. u is subcarrier spacing index

,

일 때, 시작 인터레이스 m₀와 연속된 인터레이스 수

로 구성될 수 있으며, 그 값은 다음과 같다.- When the subcarrier spacing is 15 kHz (u=0), RB allocation information for an interlace set can be notified from a base station to a terminal with m ₀ + l indices. In addition, the resource allocation field can be composed of a resource indicator value (RIV). The resource indicator value

,

When the starting interlace m ₀ and the number of consecutive interlaces

It can be composed of , and its values are as follows:

thenif

then

else

일 때, 자원 지시자 값은 시작 인터레이스 인덱스 m0와 l 값들로 구성되며 표 13와 같이 구성될 수 있다.The resource indicator value is

When this happens, the resource indicator value is composed of the start interlace index m0 and l values and can be configured as shown in Table 13.

- When the subcarrier spacing is 30 kHz ( u = 1), RB allocation information can be notified from the base station to the terminal in the form of a bitmap indicating interlaces allocated to the terminal. The size of the bitmap is M , and each bit of the bitmap corresponds to an interlace. The order of the interlace bitmap can be mapped from MSB to LSB from interlace index 0 to M -1.

Also, the least significant bit (LSB) of the FDRA field for 15 kHz and 30 kHz

,

에서는 RIV_RBset 값이 시작 RB 세트(

)와 연속된 RB 세트의 수(

)로 결정될 수 있다. RIV_RBset 값은 다음과 같이 정의될 수 있다.may mean a continuous RB set of PUSCH scheduled with DCI format 0_1. The Y bit may be configured as a resource indication value (RIV _RBset ).

,

In RIV _RBset the value is the starting RB set (

) and the number of consecutive RB sets (

) can be determined. The RIV _RBset value can be defined as follows.

thenif

then

else

은 BWP내에 포함된 RB 세트의 수를 의미하며, 상위 시그널링(또는 기 설정된)으로 설정된 캐리어 내의 가드 갭(또는 밴드)의 수로 결정될 수 있다.

refers to the number of RB sets included in the BWP, which can be determined by the number of guard gaps (or bands) within the carrier set by upper signaling (or preset).

개의 비트들로 구성되는 주파수 역역 자원 할당 정보(FDRA)를 포함한다. 여기서

는 BWP에 포함된 RB들의 수이다. 기지국은 이를 통하여 starting VRB(7-20)와 이로부터 연속적으로 할당되는 주파수 축 자원의 길이(7-25)를 설정할 수 있다.If the terminal is set to use only type-1 resource allocation through upper layer signaling (7-05), the DCI that allocates PDSCH/PUSCH to the terminal is

It contains frequency domain resource allocation information (FDRA) consisting of bits of

is the number of RBs included in the BWP. Through this, the base station can set the starting VRB (7-20) and the length of frequency axis resources (7-25) allocated sequentially therefrom.

If a terminal is configured to use both type-0 resource allocation and type-1 resource allocation through upper layer signaling (7-10), some DCIs that allocate PDSCH/PUSCH to the terminal include frequency-axis resource allocation information consisting of bits of the larger value (7-35) among the payload (7-15) for configuring type-0 resource allocation and the payload (7-20, 7-25) for configuring type-1 resource allocation. The conditions for this will be explained later. At this time, one bit can be added to the first part (MSB) of the frequency-axis resource allocation information in the DCI, and if the bit has a value of '0', it indicates that type-0 resource allocation is used, and if it has a value of '1', it indicates that type-1 resource allocation is used.

[PDSCH/PUSCH: Time Resource Allocation Related]

Below, a time domain resource allocation method for data channels in next-generation mobile communication systems (5G or NR systems) is described.

A base station can set up a table for time domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel, PDSCH) and an uplink data channel (Physical Uplink Shared Channel, PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling). A table with up to maxNrofDL-Allocations=16 entries can be set up for PDSCH, and a table with up to maxNrofUL-Allocations=16 entries can be set up for PUSCH. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a time interval in slot units between a time point when a PDCCH is received and a time point when a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to a time interval in slot units between a time point when a PDCCH is received and a time point when a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information about a position and a length of a start symbol in which a PDSCH or PUSCH is scheduled within a slot, a mapping type of the PDSCH or PUSCH, etc. For example, information such as [Table 14] or [Table 15] below may be transmitted from a base station to a terminal.

The base station can notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 signaling (e.g., DCI) (e.g., it can be indicated by the 'time domain resource allocation' field in the DCI). The terminal can obtain the time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

Referring to FIG. 8, the base station can indicate the time axis position of the PDSCH resource based on the subcarrier spacing (SCS) (μ _PDSCH , μ _PDCCH ) of the data channel and the control channel set using the upper layer, the scheduling offset (K0) value, and the start position (8-00) and length (8-05) of the OFDM symbol within a slot dynamically indicated through DCI.

FIG. 9 is a diagram illustrating an example of time-domain resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

Referring to FIG. 9, when the subcarrier spacing of a data channel and a control channel are the same (9-00, μ _PDSCH = μ _PDCCH ), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel are different (9-05, μ _PDSCH ≠ μ _PDCCH ), since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier spacing of the PDCCH.

[PUSCH: Regarding transmission method]

Next, the scheduling method of PUSCH transmission is described. PUSCH transmission can be dynamically scheduled by UL grant in DCI, or can operate by configured grant Type 1 or Type 2. Dynamic scheduling indication for PUSCH transmission is possible with DCI format 0_0 or 0_1.

Configured grant Type 1 PUSCH transmission can be semi-statically scheduled by reception of configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 16] through higher layer signaling, without reception of UL grant in DCI. Configured grant Type 2 PUSCH transmission can be semi-persistently scheduled by UL grant in DCI after reception of configuredGrantConfig not including rrc-ConfiguredUplinkGrant of [Table 16] through higher layer signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied by configuredGrantConfig of [Table 16] through higher layer signaling, except dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH provided by pusch-Config of [Table 17]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 16], the terminal applies tp-pi2BPSK in pusch-Config of [Table 17] to PUSCH transmission operated by configured grant.

Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow the codebook-based transmission method and the non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the pusch-Config of [Table 15], which is the upper signaling, is 'codebook' or 'nonCodebook'.

As described above, PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can be semi-statically configured by configured grant. If the UE is instructed to schedule PUSCH transmission via DCI format 0_0, the UE performs beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP within the serving cell, and at this time, the PUSCH transmission is based on a single antenna port. The UE does not expect scheduling for PUSCH transmission via DCI format 0_0 within a BWP where a PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE has not configured txConfig in pusch-Config of [Table 17], the UE does not expect to be scheduled with DCI format 0_1.

Next, codebook-based PUSCH transmission is described. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically by configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 or semi-statically configured via configured grant, the UE determines a precoder for PUSCH transmission based on SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (the number of PUSCH transmission layers).

At this time, SRI can be given through field SRS resource indicator in DCI or set through upper signaling srs-ResourceIndicator. When codebook-based PUSCH transmission is performed, the UE is configured with at least one SRS resource, and can be configured with up to two SRS resources. When the UE receives SRI through DCI, the SRS resource indicated by the SRI means an SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH including the SRI. In addition, TPMI and transmission rank can be given through field precoding information and number of layers in DCI or set through upper signaling precodingAndNumberOfLayers. TPMI is used to indicate a precoder to be applied to PUSCH transmission. If the UE is configured with one SRS resource, TPMI is used to indicate a precoder to be applied in the configured one SRS resource. When a terminal is configured with multiple SRS resources, TPMI is used to indicate the precoder to be applied in the SRS resource indicated through SRI.

A precoder to be used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper layer signaling, SRS-Config. In codebook-based PUSCH transmission, the UE determines a codebook subset based on TPMI and codebookSubset in the upper layer signaling, pusch-Config. The codebookSubset in the upper layer signaling, pusch-Config, can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability that the UE reports to the base station. If the UE reports 'partialAndNonCoherent' as the UE capability, the UE does not expect the value of codebookSubset in the upper layer signaling to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the UE reports 'nonCoherent' as the UE capability, the UE does not expect the value of codebookSubset in the upper signaling to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper signaling SRS-ResourceSet points to two SRS antenna ports, the UE does not expect the value of codebookSubset in the upper signaling to be set to 'partialAndNonCoherent'.

A terminal can receive one SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource in the corresponding SRS resource set can be indicated via SRI. If multiple SRS resources are set in an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal expects that the value of nrofSRS-Ports in the upper signaling SRS-Resource is set to the same value for all SRS resources.

The terminal transmits to the base station one or more SRS resources included in the SRS resource set in which the usage value is set to 'codebook' according to upper signaling, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. At this time, in codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and is included in the DCI. Additionally, the base station includes in the DCI information indicating TPMI and rank to be used by the terminal for PUSCH transmission. The terminal performs PUSCH transmission by applying the indicated rank and the precoder indicated by the TPMI based on the transmission beam of the corresponding SRS resource using the SRS resource indicated by the SRI.

Next, non-codebook based PUSCH transmission is described. Non-codebook based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can operate semi-statically by configured grant. If at least one SRS resource is configured in an SRS resource set in which the value of usage in upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be scheduled for non-codebook based PUSCH transmission through DCI format 0_1.

For an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be configured with one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE can perform calculation of a precoder for SRS transmission through measurement of the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the UE is less than 42 symbols, the UE does not expect information on the precoder for SRS transmission to be updated.

If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of the connected NZP CSI-RS is indicated when the value of the field SRS request in DCI format 0_1 or 1_1 is not '00'. At this time, the DCI must not indicate cross carrier or cross BWP scheduling. In addition, if the value of SRS request indicates the presence of the NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field is transmitted. At this time, the TCI states set for the scheduled subcarriers are not set to QCL-TypeD.

If a periodic or semi-persistent SRS resource set is configured, the associated NZP CSI-RS can be indicated via the associatedCSI-RS in the upper layer signaling SRS-ResourceSet. For non-codebook based transmission, the terminal does not expect that the upper layer signaling spatialRelationInfo for SRS resources and the associatedCSI-RS in the upper layer signaling SRS-ResourceSet are configured together.

When multiple SRS resources are set, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI can be indicated through the field SRS resource indicator in the DCI or set through the upper signaling srs-ResourceIndicator. Similar to the codebook-based PUSCH transmission described above, when the UE is provided with an SRI through the DCI, the SRS resource indicated by the SRI means an SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH including the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability that the UE reports to the base station. At this time, the SRS resources that the UE simultaneously transmits occupy the same RB. The UE sets one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

The base station transmits one NZP-CSI-RS associated with an SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on a result measured upon reception of the NZP-CSI-RS. When the terminal transmits one or more SRS resources within the SRS resource set of which usage is set to 'nonCodebook' to the base station, the terminal applies the calculated precoder, and the base station selects one or more SRS resources from the received one or more SRS resources. At this time, in non-codebook based PUSCH transmission, SRI represents an index that can express a combination of one or more SRS resources, and the SRI is included in the DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station can be the number of transmission layers of the PUSCH, and the terminal transmits the PUSCH by applying the precoder applied to SRS resource transmission for each layer.

[CA/DC related]

FIG. 10 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, dual connectivity situation according to one embodiment of the present disclosure.

Referring to FIG. 10, the wireless protocol of the next-generation mobile communication system consists of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) in the terminal and NR base station, respectively.

Key features of NR SDAP (S25, S70) may include some of the following:

- Transfer of user plane data

- Mapping between a QoS flow and a DRB for both DL and UL

- Marking QoS flow ID in both DL and UL packets

- Ability to map reflective QoS flow to data bearer for the UL SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

For the above SDAP layer device, the terminal can be configured by an RRC message for each PDCP layer device, by bearer, or by logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and if the SDAP header is configured, the terminal can instruct the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a desired service.

The main functions of NR PDCP (S30, S65) may include some of the following functions:

- Header compression and decompression (ROHC only)

- Transfer of user data function

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- Reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission function (Retransmission of PDCP SDUs)

- Ciphering and deciphering functions

- Timer-based SDU discard in uplink.

The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of directly transmitting data without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

The main functions of NR RLC (S35, S60) may include some of the following functions:

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection function

- Error detection function (Protocol error detection)

- RLC SDU discard function

- RLC re-establishment function

In the above, the in-sequence delivery function of the NR RLC device means the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering a single RLC SDU that is originally divided into multiple RLC SDUs and received, a function of rearranging received RLC PDUs based on the RLC SN (sequence number) or the PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of the NR RLC device may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU if there is a lost RLC SDU, or may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of the NR RLC device may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU. In addition, the RLC PDUs may be processed in the order they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device regardless of the order (out-of sequence delivery), or in the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and delivered to the PDCP device. The above NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

The out-of-sequence delivery function of the NR RLC device mentioned above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing and arranging the RLC SN or PDCP SN of received RLC PDUs to record any lost RLC PDUs.

NR MAC (S40, S55) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

- Mapping function (Mapping between logical channels and transport channels)

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting function

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification function

- Transport format selection function

- Padding function

The NR PHY layer (S45, S50) can perform operations of channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to a higher layer.

The above wireless protocol structure can have various detailed structures changed depending on the carrier (or cell) operation method. For example, if a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure having a single structure for each layer, such as S00. On the other hand, if the base station transmits data to a terminal based on CA (carrier aggregation) using multiple carriers in a single TRP (transmission and reception point), the base station and the terminal use a protocol structure having a single structure up to RLC, but multiplexing the PHY layer through the MAC layer, such as S10. As another example, if the base station transmits data to a terminal based on DC (dual connectivity) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure having a single structure up to RLC, but multiplexing the PHY layer through the MAC layer, such as S20.

Referring to the above-described PDCCH and beam setting related descriptions, PDCCH repetitive transmission is not supported in current Rel-15 and Rel-16 NR, so it is difficult to achieve required reliability in scenarios requiring high reliability such as URLLC. In the present disclosure, a method for repetitively transmitting PDCCH through multiple transmission points (TRPs) can be provided. According to the present disclosure, PDCCH reception reliability of a terminal can be improved. Specific methods are specifically described in the following embodiments.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. An embodiment of the present disclosure can be applied, for example, to a system such as FDD (Frequency Division Duplex), TDD (Time Division Duplex), or XDD (Cross Division Duplex), but is not limited thereto. In the present disclosure below, upper signaling (or upper layer signaling) may be a signal transmission method or signal transmitted from a base station to a terminal using a downlink data channel of a physical layer, or from a terminal to a base station using an uplink data channel of a physical layer. For example, the upper signaling (or upper layer signaling) may be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC control element; MAC CE), but is not limited thereto.

In the present disclosure below, when a terminal determines whether cooperative communication is applied, various methods may be used, such as, but not limited to, PDCCH(s) allocating PDSCH to which cooperative communication is applied having a specific format, or PDCCH(s) allocating PDSCH to which cooperative communication is applied including a specific indicator indicating whether cooperative communication is applied, or PDCCH(s) allocating PDSCH to which cooperative communication is applied being scrambled with a specific RNTI, or assuming cooperative communication application in a specific section indicated to a higher layer. For the convenience of the description below, a case in which a terminal receives a PDSCH to which cooperative communication is applied based on conditions similar to the above is referred to as a NC-JT (Non-Coherent Joint Transmission) case. That is, the NC-JT case in the present disclosure includes reception of a PDSCH to which cooperative communication is applied, and whether cooperative communication is applied can be identified based on at least one or a combination of at least one of the above-described conditions/methods.

In the present disclosure below, determining the priority between A and B can be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

In the following, the present disclosure explains the above examples through a number of embodiments, but these are not independent and one or more embodiments may be applied simultaneously or in combination.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Hereinafter, a base station is a subject that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Hereinafter, embodiments of the present disclosure will be described using a 5G system as an example, but embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included here. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure as judged by a person skilled in the art. One embodiment of the present disclosure may be applied to an FDD, TDD, or XDD system, but is not limited thereto.

In addition, when describing the present disclosure, if it is judged that a specific description of a related function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the present disclosure.

In describing the present disclosure below, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

- MIB (Master Information Block)

- SIB (System Information Block) or SIB

- RRC (Radio Resource Control)

- MAC (Medium Access Control) CE (Control Element)

In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more of the following physical layer channels or signaling methods.

- PDCCH (Physical Downlink Control Channel)

- DCI (Downlink Control Information)

- UE-specific DCI

- Group common DCI

- Common DCI

- Scheduling DCI (DCI used for scheduling downlink or uplink data, for example)

- Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

- PUCCH (Physical Uplink Control Channel)

- UCI (Uplink Control Information)

[MC-DCI related]

In the present disclosure, one DCI may be a Single-DCI or may be one DCI format, and multiple DCIs may be Multi-DCI or may be multiple DCI formats. In the present disclosure, one DCI may be one PDCCH and/or may be transmitted and received through one PDCCH, and multiple DCIs may be multiple PDCCHs and/or may be transmitted and received through multiple PDCCHs.

In general, a terminal receives one DCI, and the one DCI may include scheduling information for one cell. For example, in case of DCI format 0_0/0_1/0_2, one PUSCH may be scheduled for one uplink cell. Also, in case of DCI format 1_0/1_1/1_2, one PDSCH may be scheduled for one downlink cell. Here, the cell to be scheduled may be indicated by the CIF (carrier indication field) of the DCI format.

However, according to this method, when PDSCH or PUSCH is scheduled in each of a plurality of cells, multiple DCIs must be transmitted and received. Therefore, a lot of DCI overhead may occur. In order to reduce the DCI overhead, one DCI may schedule PDSCH or PUSCH for each of a plurality of cells. This may be conveniently called MC-DCI (Multi-cell DCI). In the present disclosure, MC-DCI may be one DCI that schedules PDSCH and/or PUSCH for each of a plurality of cells. In the present disclosure, the DCI that schedules PDSCH for each of a plurality of cells may be DCI format 1_3. Additionally, the DCI that schedules PUSCH for each of a plurality of cells may be DCI format 0_3.

The cells that can be scheduled in MC-DCI can be set by a higher layer. For example, it is assumed that MC-DCI can schedule cell 0, cell 1, cell 2, and cell 3 (simultaneously). When the terminal receives the MC-DCI, the terminal can receive scheduling information for cell 0, cell 1, cell 2, and cell 3. That is, the terminal can obtain scheduling information for cell 0, cell 1, cell 2, and cell 3 from the MC-DCI. For example, it can be set from a higher layer that MC-DCI can schedule cell 0, cell 1, cell 2, and cell 3. Here, the scheduling information can include time domain resource allocation (TDRA) information and/or frequency domain resource allocation (FDRA) information through which data channels (PDSCH for downlink, PUSCH for uplink) are transmitted and received in each cell. Accordingly, the terminal can obtain scheduling information of each cell through the MC-DCI and transmit and receive data channels to each cell.

In certain circumstances, a base station may not be able to schedule all cells set for a terminal. Scheduling may not be possible for at least some of the multiple cells set by the base station for a terminal. For example, a base station may set four cells (e.g., cell 0, cell 1, cell 2, and cell 3) to be scheduled for a terminal with MC-DCI, but some of the cells may not be able to be scheduled, for example, because they are scheduled for other terminals, the channel conditions are bad, or for other various reasons. In this case, the base station must be able to indicate to the terminal the scheduling cells among the preset cells scheduled with MC-DCI. In other words, the base station must be able to indicate to the terminal one or more cells that are (actually) scheduled among the multiple cells set to be scheduled with MC-DCI.

The terminal can obtain information indicating cells co-scheduled cells among the preset cells (e.g., cell 0, cell 1, cell 2, and cell 3) simultaneously scheduled with the current MC-DCI from the MC-DCI. That is, one or more cells (actually) simultaneously scheduled through the MC-DCI among a plurality of cells configured to be scheduled with the MC-DCI can be identified based on the MC-DCI. More specifically, the base station can configure a table including cells simultaneously scheduled for the terminal. For example, a row of the table can have a unique index. The index of each row can include the indexes of cells that are simultaneously scheduled (and/or each row). For example, {cell 0, cell 1} can be configured for row 0, {cell 2, cell 3} for row 1, and {cell 0, cell 1, cell 2, cell 3} for row 2. An example of a table set for a terminal can be found in Table 18.

The terminal can obtain a value indicating an index of the row from the MC-DCI. Accordingly, the terminal can determine a cell to be scheduled based on the value. For example, the MC-DCI can include information about an index of a row, and the terminal can identify a cell to be scheduled based on the index of the row obtained from the MC-DCI and the table. For example, if row 0 is indicated from the MC-DCI, the terminal can identify that cell 0 and cell 1 are scheduled cells. For example, if row 1 is indicated from the MC-DCI, the terminal can identify that cell 2 and cell 3 are scheduled cells. For example, if row 2 is indicated from the MC-DCI, the terminal can identify that cell 0, cell 1, cell 2, and cell 3 are scheduled cells.

In the present disclosure, a table is set for a mapping relationship between a scheduled cell (or an index of a scheduled cell) and an index indicated from a DCI, and a scheduled cell can be identified based on the table and the index indicated from the DCI.

The terminal can obtain information about the cell scheduled from MC-DCI. At least MC-DCI can include two types of DCI fields as follows.

The first type is a type in which information of one DCI field is commonly applied to multiple cells for which information is scheduled. For example, downlink assignment index, TPC command for scheduled PUCCH, PUCCH resource indicator, PDSCH-to-HARQ_feedback timing indicator fields, etc. can be commonly applied to multiple cells for which information of one DCI field is scheduled.

The second type includes a block corresponding to each of a plurality of scheduled cells in a single DCI field, and information of each block can be applied to the corresponding cell. For example, a Frequency domain resource assignment (FDRA) field, a Modulation and coding scheme (MCS) field, a New data indication (NDI) field, a HARQ process number field, etc. can be of the second type. When the DCI field of the second type includes a plurality of blocks, the lengths (payload sizes) of the blocks can be different. For example, when the FDRA field includes a first block for the first cell and a second block for the second cell, the lengths of the first block and the second block can be the same or different. For example, the length of the first block can be 10 bits, and the length of the second block can be 5 bits. The FDRA field can be extended to DCI fields included in the second type as an example.

The table below shows an example of DCI format 0_3.

[Regarding BWP changes]

A terminal can receive a DCI format including a Bandwidth part indicator field. The DCI format can be received at a PDCCH monitoring occasion of a currently activated BWP (a currently activated BWP). The Bandwidth part indicator field can indicate a BWP to be activated in the future (i.e., a BWP to be newly activated after receiving a DCI including the Bandwidth part indicator field). Therefore, after receiving the DCI format, the terminal activates the BWP indicated by the Bandwidth part indicator field. That is, after receiving the DCI format, the terminal can receive a PDSCH or transmit a PUSCH at the BWP indicated by the Bandwidth part indicator field. For convenience in the following description, the indicated BWP refers to the BWP indicated by the Bandwidth part indicator field.

For reference, each BWP is assigned/assigned/set a unique index. The Bandwidth part indicator field can indicate said unique index.

In the following description, if the currently activated BWP and the indicated BWP are different, the DCI format may be called a DCI that indicates a BWP change. And, the process of changing the currently activated BWP to the indicated BWP may be called a BWP change (BWP switching or BWP change).

For reference, in the case of MC-DCI, the Bandwidth part indicator field can indicate one value for multiple cells. For example, if '1' is indicated in the Bandwidth part indicator field, the BWP indicated for each of the multiple cells can be the BWP corresponding to '1'. Therefore, in the case of MC-DCI, a BWP change can be indicated for multiple cells at the same time.

When a terminal receives a DCI instructed to change a BWP, the terminal can interpret the information of the received DCI according to the information of the instructed BWP. The process of interpreting the information of the DCI received by the terminal according to the information of the instructed BWP can be as follows.

- The terminal can determine the length of each DCI field and the DCI length based on the information set in the currently activated BWP. The terminal can blind decode the PDCCH in the PDCCH monitoring occasion of the currently activated BWP based on the determined length of the DCI. For convenience, the DCI field obtained here can be called a received DCI field.

- The terminal can determine the length of the required DCI field based on the information set in the indicated BWP. This length can be called the required DCI field length. Note that the length of the received DCI field (the length of the DCI field determined based on the information set in the currently activated BWP) may be independent of the indicated BWP. That is, the length of the received DCI field may be different from the length of the DCI field required in the indicated BWP.

- If the length of the received DCI field is longer than the length of the required DCI field, the most significant bit (MSB) of the received DCI field can be removed to match the length of the required DCI field. For example, if the length of the received DCI field is 10 bits and is [b0,b1,b2,b3,b4,b5,b6,b7,b8,b9], if the length of the required DCI field is 6 bits, the MSB 4 bits can be excluded, and the DCI field can be interpreted using the remaining 6 bits, [b4,b5,b6,b7,b8,b9]. This process can be called truncation.

- If the length of the received DCI field is shorter than the length of the required DCI field, '0' can be added to the most significant bit (MSB) of the received DCI field to match the length of the required DCI field. For example, if the length of the received DCI field is 10 bits and is [b0,b1,b2,b3,b4,b5,b6,b7,b8,b9], then if the length of the required DCI field is 2 bits, '00', which is 2 bits, is added to the MSB, so that the DCI field can be interpreted using [0,0,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9], which is 12 bits.

The series of processes can be called DCI field size alignment.

The present disclosure describes a method for performing DCI field length alignment in MC-DCI. More specifically, in MC-DCI, a DCI field may be a second type DCI field. That is, each DCI field may include a plurality of blocks. Each block may correspond to each cell to be scheduled.

In the present disclosure, DCI field length alignment can be performed using the following two methods.

In the first method, the terminal can apply the DCI field length alignment described above on a block-by-block basis. This method can be called block-level length alignment or “per block” length alignment. More specifically,

- The terminal can determine the length of each DCI field and the DCI length based on the information set in the currently activated BWP. The terminal can blind decode the PDCCH in the PDCCH monitoring occasion of the currently activated BWP based on the length of the DCI. For convenience, the DCI field obtained here can be called a reception DCI field. The reception DCI field can include a plurality of blocks. The length of each of the plurality of blocks included in the reception DCI field can be determined.

- The terminal can determine the length of the required DCI field based on the information set in the indicated BWP. This length can be called the required DCI field length. For reference, the length of the received DCI field may be unrelated to the indicated BWP. That is, the length of the received DCI field may be different from the length of the required DCI field in the indicated BWP. For reference, the required DCI field may include a plurality of blocks. And the length of each of the plurality of blocks included in the required DCI field may be determined.

- If the length of a block of the received DCI field is longer than the length of a block of the required DCI field, the most significant bit (MSB) of the block of the received DCI field may be removed to match the length of the block of the required DCI field. If the received DCI field includes multiple blocks, the length may be adjusted for each block.

- If the length of the block of the received DCI field is shorter than the length of the block of the required DCI field, '0' is added to the most significant bit (MSB) of the block of the received DCI field to match the length of the block of the required DCI field.

- Fig. 11(a) is a drawing showing an example. Referring to Fig. 11(a), let us assume that the reception DCI field includes two blocks. Let each block be 10 bits. That is, the length of the reception DCI field is 20 bits. Let this be [b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19]. Here, the preceding 10 bits are 10 bits corresponding to the first block, and the following 10 bits are 10 bits corresponding to the second block. Let us assume that the length of the first block included in the required DCI field is 12 bits, and the length of the second block is 5 bits. That is, the required DCI field may require a total of 17 bits.

- The terminal can match the length of the first block. The length of the first block of the reception DCI field is 10 bits and the length of the first block of the required DCI field is 12 bits, so 2 bits '0,0' can be added to the MSB of the first block of the reception DCI field. Therefore, the first block of the required DCI field can be [0,0,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9]. The terminal can match the length of the second block. The length of the second block of the reception DCI field is 10 bits and the length of the second block of the required DCI field is 5 bits, so 5 bits can be removed from the MSB of the second block of the reception DCI field. Therefore, the second block of the required DCI field can be [b15,b16,b17,b18,b19].

- Fig. 12(a) is a drawing showing an example. Referring to Fig. 12(a), assume that the reception DCI field includes two blocks. Assume that each block is 5 bits. That is, the length of the reception DCI field is 10 bits. Let this be [b0, b1, b2, b3, b4, b5, b6, b7, b8, b9]. Here, the preceding 5 bits are 5 bits corresponding to the first block, and the following 5 bits are 5 bits corresponding to the second block. Assume that the length of the first block included in the required DCI field is 10 bits, and the length of the second block is 10 bits. That is, the required DCI field may require a total of 20 bits.

- The terminal can match the length of the first block. Since the length of the first block of the reception DCI field is 5 bits and the length of the first block of the required DCI field is 10 bits, 5 bits '0,0,0,0,0' can be added to the MSB of the first block of the reception DCI field. Therefore, the first block of the required DCI field can be [0,0,0,0,0,b0,b1,b2,b3,b4]. The terminal can match the length of the second block. Since the length of the second block of the reception DCI field is 5 bits and the length of the second block of the required DCI field is 10 bits, 5 bits '0,0,0,0,0' can be added to the MSB of the second block of the reception DCI field. Therefore, the second block of required DCI fields could be [0,0,0,0,0,b5,b6,b7,b8,b9].

The second method is for the terminal to use the DCI field length alignment described above. This method can be called DCI field level length alignment or “per field” length alignment. More specifically,

- The terminal can determine the length of each DCI field and the DCI length based on the information set in the currently activated BWP. The terminal can blind decode the PDCCH in the PDCCH monitoring occasion of the currently activated BWP based on the length of the DCI. For convenience, the DCI field obtained here can be called a reception DCI field. The reception DCI field can include a plurality of blocks. The length of each of the plurality of blocks included in the reception DCI field can be determined.

- The terminal can determine the length of the required DCI field based on the information set in the indicated BWP. This length can be called the required DCI field length. For reference, the length of the received DCI field may be unrelated to the indicated BWP. That is, the length of the received DCI field may be different from the length of the required DCI field in the indicated BWP. For reference, the required DCI field may include a plurality of blocks. And the length of each of the plurality of blocks included in the required DCI field may be determined.

- If the length of the received DCI field is longer than the length of the required DCI field, the most significant bit (MSB) of the received DCI field may be removed to match the length of the required DCI field. At this time, the length of each block included in the received DCI field and the length of each block included in the required DCI field may not be considered.

- Fig. 11(b) is a drawing showing an example. Referring to Fig. 11(b), let us assume that the reception DCI field includes two blocks. Let each block be 10 bits. That is, the length of the reception DCI field is 20 bits. Let this be [b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19]. Here, the preceding 10 bits are 10 bits corresponding to the first block, and the following 10 bits are 10 bits corresponding to the second block. Let us assume that the length of the first block included in the required DCI field is 12 bits, and the length of the second block is 5 bits. That is, the required DCI field may require a total of 17 bits. Therefore, the terminal can obtain 17 bits of [b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19] by removing the MSB 3 bits of the received DCI field. Then, for the first block interpretation, 12 bits of [b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14] can be used, and for the second block interpretation, 5 bits of [b15,b16,b17,b18,b19] can be used.

- If the length of the received DCI field is shorter than the length of the required DCI field, '0' may be added to the most significant bit (MSB) of the received DCI field to match the length of the required DCI field. At this time, the length of each block included in the received DCI field and the length of each block included in the required DCI field may not be considered.

- Fig. 12(b) is a drawing showing an example. Referring to Fig. 12(b), assume that the reception DCI field includes two blocks. Assume that each block is 5 bits. That is, the length of the reception DCI field is 10 bits. Let this be [b0, b1, b2, b3, b4, b5, b6, b7, b8, b9]. Here, the preceding 5 bits are 5 bits corresponding to the first block, and the following 5 bits are 5 bits corresponding to the second block. Assume that the length of the first block included in the required DCI field is 10 bits, and the length of the second block is 10 bits. That is, the required DCI field may require a total of 20 bits. Therefore, the terminal can obtain 20 bits of [0,0,0,0,0,0,0,0,0,0,0,0,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9] by adding 10 bits of '0,0,0,0,0,0,0,0,0,0,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9] to the MSB of the received DCI field. And, for the first block interpretation, the preceding 10 bits of [0,0,0,0,0,0,0,0,0,0,0] can be used, and for the second block interpretation, the following 10 bits of [b1,b2,b3,b4,b5,b6,b7,b8,b9] can be used.

The terminal can be configured with one of the first method and the second method from the base station. That is, the upper layer signal of the base station can configure MC-DCI and can also be configured with one of the first method and the second method. The terminal can use one of the first method and the second method according to the configured method. The terminal can adjust the length of each DCI field based on the configured method. And, the terminal can interpret the DCI field. The terminal can receive a PDSCH or transmit a PUSCH in the indicated BWP of a plurality of cells according to the interpretation.

For reference, the terminal may be set to one of the first method and the second method for all DCI fields. Alternatively, the terminal may be set to one of the first method and the second method for each of the DCI fields. That is, the first DCI field may be set to the first method, and the second DCI field may be set to the second method.

For reference, the terminal may be set to either the first or second method for all BWP changes. Alternatively, the terminal may be set to either the first or second method depending on the currently activated BWP. That is, if the currently activated BWP is BWP#1, the first method may be set, and if the currently activated BWP is BWP#2, the second method may be set.

For reference, the terminal may be set to one of the first method and the second method for every BWP change. Alternatively, the terminal may be set to one of the first method and the second method according to the indicated BWP. That is, if the indicated BWP is BWP#1, the first method may be set, and if the indicated BWP is BWP#2, the second method may be set.

For reference, the terminal may be set to one of the first method and the second method for every BWP change. Alternatively, the terminal may be set to one of the first method and the second method depending on the combination of the currently activated BWP and the indicated BWP. That is, if the currently activated BWP is BWP#1 and the indicated BWP is BWP#2, the first method may be set, and if the currently activated BWP is BWP#2 and the indicated BWP is BWP#1, the second method may be set.

In the above examples, BWP#1 and BWP#2 are just examples, and the same idea of disclosure can be applied to other BWPs.

This process is illustrated in the flowchart in Fig. 13.

In the present disclosure, a method is provided in which a terminal selectively uses one of the first and second methods without separate settings. With reference to FIGS. 11 and 12 above, the following can be observed.

- Referring to Fig. 11, the length of the received DCI field is 20 bits and the length of the required DCI field is 17 bits. However, in the case of the first method, only 15 bits out of the 20 bits can be used. And 2 bits '0,0' can be added to determine 17 bits. In the case of the second method, 17 bits out of the 20 bits can be used. Therefore, the first method is not efficient in bit usage. That is, when the length of the received DCI field is equal to or longer than the length of the required DCI field, the second method can be more efficient.

- Referring to Fig. 12, the length of the received DCI field is 10 bits, and the length of the required DCI field is 20 bits. In the second method, all bits of the first block may be '0'. However, in the first method, the first block and the second block may include 5 bits. That is, when the length of the received DCI field is shorter than the length of the required DCI field, the first method may be more efficient.

According to the above observation, in one embodiment of the present disclosure, the terminal can determine the first method and the second method as follows.

The terminal can set MC-DCI from the base station. When the terminal receives MC-DCI instructing BWP change, the terminal can determine the length of the received DCI field and the length of the required DCI field for each DCI field. Here, the length of the received DCI field is determined based on the settings set for the BWP (or BWP pair) that monitors the MC-DCI as the length of the DCI field included in the received MC-DCI. The length of the required DCI field is determined based on the settings set for the indicated BWP (or BWP pair). The terminal can select one of the first method and the second method based on the length of the received DCI field and the length of the required DCI field for each DCI field.

For example, if the length of the received DCI field is equal to or longer than the length of the required DCI field, the terminal may select the second method. If the length of the received DCI field is shorter than the length of the required DCI field, the terminal may select the first method.

For example, if the length of the received DCI field is longer than the length of the required DCI field, the terminal may select the second method. If the length of the received DCI field is shorter than the length of the required DCI field, the terminal may select the first method. If the length of the received DCI field is the same as the length of the required DCI field, separate length alignment may not be performed.

For example, if the length of the received DCI field is equal to or longer than the length of the required DCI field, the terminal can select the second method. If the length of the received DCI field is shorter than the length of the required DCI field, the terminal can be set to the first or second method from the base station. That is, the terminal can be set to the first or second method from the base station through a higher layer signal (RRC signal). The set method can be used if the length of the received DCI field is shorter than the length of the required DCI field.

The terminal can perform length alignment of the DCI field based on a determined method for each DCI field. And the terminal can interpret the DCI field. The terminal can perform PDSCH reception or PUSCH transmission in the indicated BWP of multiple cells according to the interpretation.

This process is illustrated in the flowchart in Fig. 14.

The operation of the terminal corresponding to Fig. 14 is shown in the following table.

Figure 15 is another example considered in the present disclosure.

In Fig. 15, the receiving DCI field may include two blocks. The length of the first block of the receiving DCI field may be 5 bits, and the length of the second block may be 5 bits. Therefore, the length of the receiving DCI field may be 10 bits. The required DCI field may include two blocks. The length of the first block of the receiving DCI field may be 10 bits, and the length of the second block may be 3 bits. Therefore, the length of the required DCI field may be 13 bits.

Fig. 15(a) shows the length alignment of the DCI field according to the first method. The first block may have 5 bits '0,0,0,0,0' added to the MSB, and the second block may have 2 bits of the MSB excluded. Therefore, according to the first method, the terminal may use only 8 bits out of 10 bits included in the reception DCI field.

Fig. 15(a) shows the length alignment of the DCI field according to the second method. 3 bits '0,0,0' are added to the MSB of the reception DCI field, so that 13 bits, which are the required DCI field, can be determined. The first 10 bits of the 13 bits may correspond to the first block, and the last 3 bits may correspond to the second block. Accordingly, the 10 bits of the first block may include 3 bits '0,0,0'. According to the second method, the terminal may use all 10 bits included in the reception DCI field.

Therefore, the second method may be a better method from the perspective of bit usage efficiency of the received DCI field.

In one embodiment of the present disclosure, a terminal can select a method that maximizes bit usage efficiency.

The terminal can be configured with MC-DCI from the base station. When the terminal receives MC-DCI instructing a BWP change, the terminal can determine the length of the received DCI field and the length of the required DCI field for each DCI field. Here, the length of the received DCI field is determined based on the settings set in the BWP (or BWP pair) that monitors the MC-DCI as the length of the DCI field included in the received MC-DCI. The length of the required DCI field is determined based on the settings set in the indicated BWP (or BWP pair).

The terminal can determine the number of bits included in a required DCI field among the bits included in the reception DCI field using the first method. That is, the number of bits used for interpretation among the bits included in the reception DCI field can be determined. The terminal can determine the number of bits included in a required DCI field among the bits included in the reception DCI field using the second method. That is, the number of bits used for interpretation among the bits included in the reception DCI field can be determined.

The terminal can determine one method based on the number of bits according to the first method and the number of bits according to the second method. Here, a method corresponding to a greater number of bits can be selected. For example, if the number of bits according to the first method is greater than the number of bits according to the second method, the first method can be selected. For reference, if the two methods have the same number, the terminal can determine one of the first method and the second method as a different method. Here, the different method can be a predetermined method (for example, the second method) or a method set by a higher layer signal.

The terminal can perform length alignment of the DCI field based on a determined method for each DCI field. And the terminal can interpret the DCI field. The terminal can perform PDSCH reception or PUSCH transmission in the indicated BWP of multiple cells according to the interpretation.

This process is illustrated in the flowchart in Fig. 16.

In the previous embodiment, the terminal maximized the bit usage efficiency of the reception DCI field. Referring to Fig. 15, the terminal can select the second method. However, referring to Fig. 15(b), the terminal can confirm that '0's are added to only one block. That is, although the bit usage efficiency of the reception DCI field is maximized, differences may occur in the blocks.

Another embodiment of the present disclosure is a method of distributing bits evenly to each block while maximizing bit usage efficiency of a received DCI field.

The terminal can determine the length of the received DCI field. This length can be referred to as L. For reference, the received DCI field can include multiple blocks. Let's assume that it includes N blocks. And let the length of each block be L_1, L_2, ..., L_N. Here, L_1+L_2+... +L_N= L.

The terminal can determine the length of the required DCI field. This length can be referred to as R. Note that the received DCI field can include multiple blocks. Let's assume that it includes N blocks. And let the length of each block be R_1, R_2, ..., R_N. Here, R_1+R_2+... +R_N= R.

The terminal can change the length of blocks of the received DCI field to be proportional to the length of blocks of the required DCI field. Let the lengths of the changed blocks of the received DCI field be S_1, S_2, ..., S_N. S_1+S_2+... +S_N=L. In order to make it proportional to the length of blocks of the required DCI field, S_i can be obtained as follows.

S_i = f(L*(R_i/R)), i=1,… N-1

S_N = L-(S_1+S_2+…S_{N-1})

Here, f(x) can be one of ceil(x), floor(x), and round(x). ceil(x) is a floor function, floor(x) is a floor function, and round(x) is a rounding function.

Referring to Fig. 17, this is an example where L = 10 and R_1 = 10, R_2 = 3. The terminal can obtain S_1 = ceil(L*R_1/R) = ceil(10*10/13) = 8, S_2 = L-S_1 = 2. That is, although the terminal assumes that the 10-bit DCI field received consists of 5 bits of the first block and 5 bits of the second block, in order to adjust the length of the DCI field, it can be assumed that it consists of 8 bits of the first block and 2 bits of the second block. In addition, since the first block of the required DCI field is 10 bits, 2 bits '0,0' can be added to the first block (8 bits) of the received DCI field. Since the second block of the required DCI field is 3 bits, 1 bit '0' can be added to the second block (2 bits) of the received DCI field. Therefore, according to an embodiment of the present disclosure, the terminal can use all 10 bits of the received DCI field and evenly add '0' to the blocks.

In another method of the present disclosure, the terminal can minimize the number of blocks to which '0' is added. When '0' is added to a block by adjusting the length of the DCI field, a fixed bit value is added to the block. Therefore, the base station may not be able to freely indicate. This method is intended to correctly indicate information of as many blocks as possible.

The terminal can determine the length of the received DCI field. This length can be referred to as L. For reference, the received DCI field can include multiple blocks. Let's assume that it includes N blocks. And let the length of each block be L_1, L_2, ..., L_N. Here, L_1+L_2+... +L_N= L.

The terminal can determine the length of the required DCI field. This length can be referred to as R. Note that the received DCI field can include multiple blocks. Let's assume that it includes N blocks. And let the length of each block be R_1, R_2, ..., R_N. Here, R_1+R_2+... +R_N= R.

The terminal can change the length of blocks of the received DCI field to be proportional to the length of blocks of the required DCI field. Let the lengths of the changed blocks of the received DCI field be S_1, S_2, ... S_N. S_1+S_2+... +S_N=L. In order to make it proportional to the length of blocks of the required DCI field, S_i can be obtained as follows.

If R_1 ≤ L, then S_1 = R_1. If S_1+R_2 ≤ L, then S_2 = R_2. Continuing, if S_1+S_2+… S_{k-1}+R_k ≤ L, then S_k = R_k. If S_1+S_2+… S_{k-1}+R_k > L, then S_k = L-(S_1+S_2+…S_{k-1}), and S_{k+1}= S_{k+2}=… S_N=0. That is, the required number of bits can be allocated in the ascending order of the block indices.

In this disclosure, the ascending order of the block index is used. The block index may be the included order of the DCI field. Alternatively, the block index may be determined according to the length of the blocks included in the DCI field. For example, a shorter block may have a lower index, and a longer block may have a higher index. Using this method, bits may be preferentially assigned to blocks of shorter length, and the number of blocks to which '0' is not added may be maximized.

Another embodiment of the present disclosure is that the terminal can preferentially assign bits to a block corresponding to one (or a predetermined number) of cells so that '0' is not added to the block corresponding to the cell. This may be possible when one (or a predetermined number) of cells performs a more important role than other cells. For example, one cell may be a cell monitoring a PDCCH, a Pcell, or a cell transmitting a PUCCH. Or, it may be a cell with the lowest cell index.

Another embodiment of the present disclosure is for a case where one block of the FDRA field corresponds to all '0's added for DCI field length alignment. Referring to Fig. 12(b), the first block is [0,0,0,0,0,0,0,0,0,0,0], and the '0's here may all be '0's added for DCI field length alignment. In this case, the terminal may perform the following operations.

The terminal may consider that there is no PDSCH (or PUSCH) scheduled according to the FDRA field. That is, the terminal may not receive a PDSCH (or PUSCH) in the cell corresponding to the first block. This may be regardless of the FDRA type set for the terminal.

Alternatively, the terminal may regard the above case as an error case. That is, the base station may not set the terminal to a setting where all bits are '0' as above. When the terminal receives the DCI instructed to perform the above operation, the DCI may be discarded. The terminal may not perform the operation instructed in the discarded DCI.

The terminal can set or determine the number of blocks corresponding to the BWP indices of the cells from the base station. More specifically, the terminal can be set with one or more BWPs in the cell, and each BWP can have a unique index. The unique index can be one of 1, 2, 3, and 4. For example, Cell A (or Cell#A) is set with two BWPs, and the two BWPs can have indices of 1 and 2, Cell B (or Cell#B) is set with two BWPs, and the three BWPs can have indices of 1, 2, and 3, Cell C (or Cell#C) is set with two BWPs, and the two BWPs can have indices of 1 and 2, and Cell D (or Cell#D) is set with four BWPs, and the four BWPs can have indices of 1, 2, 3, and 4.

Each BWP of each cell may include different upper layer configurations. The terminal may determine the length of the DCI format or the length of the field included in the DCI format based on the upper layer configurations. For example, maxNrofCodeWordsScheduledByDCI may be set as upper layer configuration information for setting the number of transport blocks in one BWP of one cell. When maxNrofCodeWordsScheduledByDCI is set to 2, the terminal may determine that the PDSCH scheduled by the DCI format to the BWP of the cell may include at most two transport blocks. Accordingly, the DCI field corresponding to the BWP of the cell in the DCI format may include an MCS (modulation and coding scheme) value, an NDI (new data indicator) value, and an RV (redundancy value) value for a first transport block, and an MCS value, an NDI value, and an RV value for a second transport block. If maxNrofCodeWordsScheduledByDCI is not set to 2 for a BWP of a cell, the terminal can determine that a maximum of 1 transport block can be scheduled for the BWP of the cell in the DCI format. Accordingly, the DCI field corresponding to the BWP of the cell in the DCI format includes an MCS (modulation and coding scheme) value, an NDI (new data indicator) value, and an RV (redundancy value) value for the first transport block, but may not include an MCS value, an NDI value, and an RV value for the second transport block.

When a terminal monitors a DCI format for scheduling PDSCHs to multiple cells, the length of the DCI format or the length of DCI fields included in the DCI format can be determined based on the BWP already activated in each cell. That is, the already activated BWP of Cell A (Cell#A) to Cell D (Cell#D) can be a BWP with an index of 1.

A DCI format that schedules PDSCHs to multiple cells may include a single BWP index. For example, the DCI format may indicate a BWP index value of 1. In this case, the DCI format may schedule PDSCHs to multiple cells to a BWP whose BWP index is 1. If there is no BWP corresponding to the index in a cell, the UE may schedule the PDSCH to an already activated BWP, not a BWP corresponding to the index in the cell.

If a DCI format for scheduling PDSCH to multiple cells indicates a BWP other than an already activated BWP, the length of the DCI field requested by the terminal may be different. More specifically, the length of the DCI field determined according to the upper layer configuration of the activated BWP may be the first length, but the length of the DCI field determined according to the upper layer configuration of the indicated BWP may be the second length. The terminal may obtain the DCI field of the first length from the DCI format, but since the BWP for which the PDSCH is scheduled is the indicated BWP, the DCI field of the second length may be required. For this purpose, the operation of the terminal is defined as in Table 19.

Referring to Table 19, if the first length is longer than the second length, the terminal can interpret the DCI field by using only the first length among the DCI fields of the first length. If the first length is shorter than the second length, the terminal can interpret the DCI field by padding the MSB (most significant bit) of the DCI field of the first length with '0' to make it the first length.

Referring to Table 19, when the DCI field includes multiple blocks, the above operation can be performed for each block. In the following description, performing the above operation for each block can be referred to as block-based DCI field length alignment. The present disclosure proposes a specific method for performing the above operation for each block.

In the following description, the DCI field is included in a DCI format that schedules PDSCH to multiple cells and may include at least one block.

A DCI field corresponding to an already activated BWP of cells may include a first number of blocks, and a DCI field corresponding to an indicated BWP of cells may include a second number of blocks. Here, the first number and the second number may be the same or different from each other.

For convenience of description, let the first number (N ₁ ) of blocks corresponding to the active BWP be {active-Block#1, active-Block#2, … active-Block#N ₁ }, and let the second number (N ₂ ) of blocks corresponding to the indicated BWP be {indicated-Block#1, indicated-Block#2, … indicated-Block#N ₂ }. Here, active-Block#X represents a block whose index is X among the blocks. It can have one value among the number of blocks (N ₁ ) included from X = 1. Indicated-Block#Y represents a block whose index is Y among the blocks. It can have one value among the number of blocks (N ₂ ) included from Y = 1. The indexes of blocks within the DCI field can be determined in ascending order according to the sequence.

Although the first number and the second number are the same, the cells corresponding to the blocks of the first number and the cells corresponding to the blocks of the second number may be different from each other. More specifically, let the first number and the second number be 3. The three blocks included in the DCI field corresponding to the already activated BWP of the cells may be blocks corresponding to cells A, C, and D (active-Block#1 corresponds to cell A, active-Block#2 corresponds to cell C, and active-Block#3 corresponds to cell D). However, the three blocks included in the DCI field corresponding to the indicated BWP of the cells may be blocks corresponding to cells A, B, and C (indicated-Block#1 corresponds to cell A, indicated-Block#2 corresponds to cell B, and indicated-Block#3 corresponds to cell C).

Terminal block-by-block DCI field length alignment can be performed as follows.

As a first method, DCI field length alignment per block of the terminal can be performed based on blocks with the same block index (active-Block#X and indicated-Block#Y, X=Y).

- The length of active-Block#1 can be considered as the first length and indicated-Block#1 as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#2 can be considered as the first length and indicated-Block#2 as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#3 can be considered as the first length and indicated-Block#3 as the second length, so that the first length can be adjusted to the second length.

In a second method, the block-wise DCI field length alignment of the terminal can be performed based on blocks having the same cell index corresponding to the blocks (active-Block#X and indicated-Block#Y, the cell index corresponding to active-Block#X and the cell index corresponding to indicated-Block#Y are the same). Note that a block corresponding to a specific cell may not be included in the DCI field. For example, a DCI field corresponding to an already activated BWP of cells may include blocks corresponding to cells A, C, and D (active-Block#1 corresponds to cell A, active-Block#2 corresponds to cell C, and active-Block#3 corresponds to cell D), but may not include a block corresponding to cell B. The DCI field corresponding to the indicated BWP of the cells includes blocks corresponding to cells A, B, and C (indicated-Block#1 corresponds to cell A, indicated-Block#2 corresponds to cell B, and indicated-Block#3 corresponds to cell C), but may not include a block corresponding to cell D. According to the present disclosure, the length of the blocks that are not included can be regarded as 0 bit.

- The length of active-Block#1 corresponding to cell A can be considered as the first length, and indicated-Block#1 can be considered as the second length, so that the first length can be adjusted to the second length.

- Since there is no block corresponding to cell B among the blocks {active-Block#1, active-Block#2, active-Block#3} corresponding to the already activated BWP, the first length is considered as 0 bit, and indicated-Block#2 is considered as the second length, so the first length can be adjusted to the second length.

- The length of active-Block#2 corresponding to cell C can be considered as the first length, and indicated-Block#3 can be considered as the second length, so that the first length can be adjusted to the second length.

- Since there is no block corresponding to cell D among the blocks {indicated-Block#1, indicated-Block#2, indicated-Block#3} corresponding to the first length and the indicated BWP, the second length is considered as 0 bit, and the first length can be adjusted to the second length.

When the first number and the second number are different from each other, the cells corresponding to the blocks of the first number and the cells corresponding to the blocks of the second number may be different from each other. Let the first number be 3 and the second number be 4. The three blocks included in the DCI field corresponding to the already activated BWP of the cells may be blocks corresponding to cells A, C, and D (active-Block#1 corresponds to cell A, active-Block#2 corresponds to cell C, and active-Block#3 corresponds to cell D). However, the four blocks included in the DCI field corresponding to the indicated BWP of the cells may be blocks corresponding to cells A, B, C, and D (indicated-Block#1 corresponds to cell A, indicated-Block#2 corresponds to cell B, indicated-Block#3 corresponds to cell C, and indicated-Block#4 corresponds to cell D).

Terminal block-by-block DCI field length alignment can be performed as follows.

As a first method, the DCI field length alignment of the terminal block by block can be performed based on blocks with the same block index (active-Block#X and indicated-Block#Y, X=Y). If a block with a specific index is not included in the DCI field, the terminal can regard the length of the block as 0 bits.

- The length of active-Block#1 can be considered as the first length and indicated-Block#1 as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#2 can be considered as the first length and indicated-Block#2 as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#3 can be considered as the first length and indicated-Block#3 as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#4 can be considered as the first length and indicated-Block#4 as the second length, so that the first length can be adjusted to the second length. Here, since the DCI field does not include indicated-Block#4, indicated-Block#4 can be considered as 0 bit.

In a second method, the block-wise DCI field length alignment of the terminal can be performed based on blocks having the same cell index corresponding to the blocks (active-Block#X and indicated-Block#Y, the cell index corresponding to active-Block#X and the cell index corresponding to indicated-Block#Y are the same). Note that a block corresponding to a specific cell may not be included in the DCI field. For example, a DCI field corresponding to an already activated BWP of cells may include blocks corresponding to cells A, C, and D (active-Block#1 corresponds to cell A, active-Block#2 corresponds to cell C, and active-Block#3 corresponds to cell D), but may not include a block corresponding to cell B.

- The length of active-Block#1 corresponding to cell A can be considered as the first length, and indicated-Block#1 can be considered as the second length, so that the first length can be adjusted to the second length.

- Since there is no block corresponding to cell B among the blocks {active-Block#1, active-Block#2, active-Block#3} corresponding to the already activated BWP, the first length is considered as 0 bit, and indicated-Block#2 is considered as the second length, so the first length can be adjusted to the second length.

- The length of active-Block#2 corresponding to cell C can be considered as the first length, and indicated-Block#3 can be considered as the second length, so that the first length can be adjusted to the second length.

- The length of active-Block#3 corresponding to cell D can be considered as the first length, and indicated-Block#3 can be considered as the second length, so that the first length can be adjusted to the second length.

Table 20 shows the operation of a terminal according to Method 1. Compared to Table 19, according to Table 20, when a terminal performs block-by-block DCI field length alignment, it can perform length alignment for blocks of the same index based on the index of the block.

Table 21 shows the operation of a terminal according to Method 2. Compared to Table 19, according to Table 21, when a terminal performs block-by-block DCI field length alignment, it can perform length alignment for blocks of the same cell index based on the index of the cell corresponding to the block.

FIG. 18 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

Referring to FIG. 18, the terminal may include a transceiver, which refers to a terminal receiving unit (1800) and a terminal transmitting unit (1810), a memory (not shown), and a terminal processing unit (1805), or a terminal control unit or processor. According to the communication method of the terminal described above, the transceiver (1800, 1810), the memory, and the terminal processing unit (1805) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

The transceiver can transmit and receive signals with the base station. Here, the signals can include control information and data. To this end, the transceiver can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and the RF receiver.

Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

The memory can store programs and data necessary for the operation of the terminal. In addition, the memory can store control information or data included in signals transmitted and received by the terminal. The memory can be composed of a storage medium such as ROM, RAM, a hard disk, CD-ROM, and DVD, or a combination of storage media. In addition, there can be a plurality of memories.

In addition, the processor can control a series of processes so that the terminal can operate according to the above-described embodiment. For example, the processor can control components of the terminal to receive DCI consisting of two layers and simultaneously receive multiple PDSCHs. There can be a plurality of processors, and the processor can perform component control operations of the terminal by executing a program stored in a memory.

FIG. 19 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

Referring to FIG. 19, the base station may include a transceiver, which refers to a base station receiver (1930) and a base station transmitter (1910), a memory (not shown), and a base station processing unit (1905), or a base station control unit or processor). According to the communication method of the base station described above, the transceiver (1900, 1910), the memory, and the base station processing unit (1905) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

The transceiver can transmit and receive signals with the terminal. Here, the signals can include control information and data. To this end, the transceiver can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and the RF receiver.

Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

The memory can store programs and data required for the operation of the base station. In addition, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be composed of a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories.

The processor may control a series of processes so that the base station can operate according to the above-described embodiment of the present disclosure. For example, the processor may configure two layers of DCIs including allocation information for a plurality of PDSCHs and control each component of the base station to transmit them. There may be a plurality of processors, and the processor may perform the component control operation of the base station by executing a program stored in a memory.

The methods according to the claims or embodiments described in the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

In the case of software implementation, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the disclosure.

These programs (software modules, software) may be stored in a random access memory, a non-volatile memory including a flash memory, a ROM (Read Only Memory), an Electrically Erasable Programmable Read Only Memory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM (CD-ROM), a Digital Versatile Discs (DVDs) or other forms of optical storage devices, a magnetic cassette. Or, they may be stored in a memory composed of a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

Additionally, the program may be stored in an attachable storage device that is accessible via a communications network, such as the Internet, an Intranet, a Local Area Network (LAN), a Wide LAN (WLAN), or a Storage Area Network (SAN), or a combination thereof. The storage device may be connected to the device performing the embodiments of the present disclosure via an external port. Additionally, a separate storage device on the communications network may be connected to the device performing the embodiments of the present disclosure.

In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in the singular or plural form according to the specific embodiments presented. However, the singular or plural expressions are selected to suit the presented situation for the convenience of explanation, and the present disclosure is not limited to the singular or plural components, and even if a component is expressed in the plural form, it may be composed of the singular form, or even if a component is expressed in the singular form, it may be composed of the plural form.

Meanwhile, the embodiments of the present disclosure disclosed in the present disclosure and the drawings are only specific examples to easily explain the technical contents of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it is obvious to a person having ordinary skill in the art to which the present disclosure pertains that other modified examples based on the technical idea of the present disclosure are possible. In addition, each of the above embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined and operated as a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure may be combined and operated as a base station and a terminal. In addition, although the above embodiments have been presented based on the FDD LTE system, other modified examples based on the technical idea of the above embodiments may be implemented in other systems such as the TDD LTE system, 5G, or NR system.

Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without damaging the essence of the present disclosure.

In addition, the method of the present disclosure may be implemented by combining part or all of the contents included in each embodiment within a scope that does not harm the essence of the present disclosure.

Various embodiments of the present disclosure have been described above. The description of the present disclosure as described above is for illustrative purposes, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art to which the present disclosure pertains will understand that the present disclosure can be easily modified into other specific forms without changing the technical idea or essential features of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present disclosure.

Claims (15)

In a method performed by a terminal in a wireless communication system, the method comprises: A step of receiving downlink control information including a bandwidth part (BWP) indicator field and a first field from a base station; and A step of performing DCI size alignment for the first field included in the DCI and the second field required for interpretation of the DCI format for the BWP indicated by the BWP indicator field corresponding to the first field, A method wherein, when the DCI relates to multi-cell scheduling and the first field includes a plurality of first blocks corresponding to each of the cells set for the multi-cell scheduling, the DCI size alignment is applied on a block-by-block basis. In the first paragraph, A method wherein the DCI size alignment applied based on the block unit is applied separately to each of the plurality of first blocks. In the second paragraph, the method, Further comprising a step of receiving information indicating a method of aligning the DCI size from the base station, A method in which the above information indicates either a block-based method or a field-based method. In the third paragraph, the step of performing the DCI size alignment is: If the size of a first block among the plurality of first blocks is smaller than the size of a second block of the second field corresponding to the first block, a step of adding at least one bit having a value of 0 to the first block until the size of the first block becomes equal to the size of the second block; and A method further comprising the step of using a least significant bit of the first block corresponding to the size of the second block when the size of the first block among the plurality of first blocks is larger than the size of the second block of the second field corresponding to the first block. In the third paragraph, If the above DCI relates to multi-cell scheduling and the first field does not include a plurality of first blocks corresponding to each of the cells set for the multi-cell scheduling: The above DCI size alignment is applied based on field units, The steps for performing the above DCI size alignment are: If the size of the first field is smaller than the size of the second field, adding at least one bit having a value of 0 to the first field until the size of the first field becomes equal to the size of the second field; and A method further comprising the step of using a least significant bit of the first field corresponding to the size of the second field when the size of the first field is greater than the size of the second field. In the first paragraph, The above DCI size alignment method is applied more on a field basis. In Article 6, The steps for performing the above DCI size alignment are: A step of determining a field having a larger field size among the first field and the second field; and Based on the result of the above decision, further comprising a step of performing the DCI size alignment based on either the block unit or the field unit, If the size of the first field is larger than the size of the second field, the DCI size alignment is applied based on the field unit, A method wherein, when the size of the first field is smaller than the size of the second field, the DCI size alignment is applied based on the block unit. In Article 6, The steps for performing the above DCI size alignment are: Further comprising a step of determining the number of bits included in the second field when the block-based DCI size alignment is applied among the bits included in the first field, and the number of bits included in the second field when the field-based DCI size alignment is applied among the bits included in the first field, When the number of bits included in the second field when the DCI size alignment of the block unit is applied among the bits included in the first field is greater than the number of bits included in the second field when the DCI size alignment of the field unit is applied among the bits included in the first field, the DCI size alignment is applied based on the block unit, A method in which, when the number of bits included in the second field is smaller than the number of bits included in the second field when the DCI size alignment of the block unit is applied among the bits included in the first field, the DCI size alignment is applied based on the field unit. In a wireless communication system, the terminal comprises: transceiver; and Including a controller connected to the above transceiver, The above controller, Receive downlink control information including a bandwidth part (BWP) indicator field and a first field from a base station, It is configured to perform DCI size alignment for the first field included in the DCI and the second field required for interpretation of the DCI format for the BWP indicated by the BWP indicator field corresponding to the first field, A terminal, wherein the DCI is related to multi-cell scheduling and the first field includes a plurality of first blocks corresponding to each of the cells set for the multi-cell scheduling, and the DCI size alignment is applied on a block-by-block basis. In Article 9, The DCI size alignment applied based on the above block unit is applied separately to each of the plurality of first blocks. In the 10th paragraph, the controller, Further configured to receive information indicating a method of aligning the DCI sizes from the base station, The above information indicates one of a block-based method and a field-based method, the terminal. In the 11th paragraph, the controller for performing the DCI size alignment, If the size of a first block among the plurality of first blocks is smaller than the size of a second block of the second field corresponding to the first block, at least one bit having a value of 0 is added to the first block until the size of the first block becomes equal to the size of the second block, A terminal further configured to use a least significant bit of the first block corresponding to the size of the second block of the second field when the size of the first block among the plurality of first blocks is larger than the size of the second block corresponding to the size of the second block. In Article 11, If the above DCI relates to multi-cell scheduling and the first field does not include a plurality of first blocks corresponding to each of the cells set for the multi-cell scheduling: The above DCI size alignment is applied based on field units, To perform the above DCI size alignment, the controller, If the size of the first field is smaller than the size of the second field, add at least one bit having a value of 0 to the first field until the size of the first field becomes equal to the size of the second field, A terminal further configured to use a least significant bit of the first field corresponding to the size of the second field when the size of the first field is greater than the size of the second field. In Article 9, The above DCI size alignment is applied more on a field-by-field basis, terminal. In Article 14, To perform DCI size alignment, the controller: Determine the field having a larger field size among the first field and the second field, Based on the result of the above decision, the DCI size alignment is further configured to be performed based on either the block unit or the field unit, If the size of the first field is larger than the size of the second field, the DCI size alignment is applied based on the field unit, A terminal in which, when the size of the first field is smaller than the size of the second field, the DCI size alignment is applied based on the block unit.

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